CONSERVATION OF DEEP SEA BEDS. 1041 



strong scouring tides, and water as well suited for the food 

 of oysters as that of the Bay of St. Malo, deep-sea oysters 

 would be better and more plentiful. 



B. ARTIFICIAL CAUSES. 



DREDGING. 



Oyster fishing is pursued in a very different manner in 

 different countries. Round Minorca, divers, with hammers 

 attached to the right hand, descend to the depth of a 

 dozen fathoms, and bring up in their left hand as many of 

 the bivalves as they can carry, two fishermen, usually asso- 

 ciating for the purpose, diving alternately until the boat is 

 filled. 



On the English, French, and German coasts, the 

 dredge is employed. This operation is also necessary to 

 keep down the marine vegetation, which would stifle the 

 oysters ; the engine is of iron, and very heavy (from 20 to 

 zzlbs). It is thrown overboard, and descends to the bot- 

 tom of the sea, which it ploughs and scrapes up, detaching 

 the oysters, and throwing them into a net attached to the 

 dredge. In this process oysters, large and small, are torn 

 from their native bed, some going into the net, but a 

 larger number are buried in the mud. It would be difficult 

 to imagine a more destructive process ; and when the 

 habits of the oyster are considered, it is evidently one 

 admirably contrived to destroy the race. In France oyster 

 dredging is conducted by fleets of thirty or forty boats, 

 each carrying four or five men. At a fixed hour, and under 

 the surveillance of a coast-guard in a pinnace bearing the 

 national flag, the flotilla commences the fishing. In the 

 estuary of the Thames the practice is much the same, 

 although no official surveillance is observed. Each bark is 



